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PrimMST.cpp
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176 lines (144 loc) · 3.47 KB
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// UVa OJ - 11631
#include <iostream>
#include <iomanip>
#include <algorithm>
#include <vector>
#include <set>
#include <unordered_set>
#include <map>
#include <unordered_map>
#include <queue>
#include <deque>
#include <stack>
#include <list>
#include <bitset>
#include <string>
#include <utility>
#include <iterator>
#include <fstream>
#include <sstream>
#include <numeric>
#include <functional>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cstring>
#include <cctype>
#include <climits>
#include <ctime>
#include <cassert>
using namespace std;
/* typedef starts */
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
/* typedef ends */
/* macro starts */
#define PI acos(-1.0)
#define EPS 1e-9
#define fastIO ios::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
#define sinD(degree) sin((degree * PI) / 180.0)
#define cosD(degree) cos((degree * PI) / 180.0)
#define tanD(degree) tan((degree * PI) / 180.0)
#define cotD(degree) (1.0 / tanD(degree))
#define secD(degree) (1.0 / cosD(degree))
#define cosecD(degree) (1.0 / sinD(degree))
#define asinD(value) (asin(value) * 180.0) / PI
#define acosD(value) (acos(value) * 180.0) / PI
#define atanD(value) (atan(value) * 180.0) / PI
/* macro ends */
/* function starts */
/// calculates n-th (0-based) Gray Code
template<typename dataType>
dataType nthGrayCode(dataType n)
{
return (n ^ (n >> 1));
}
/// generates all possible subsets for the given set
template<typename dataType>
void generateAllSubset(vector<dataType> &data)
{
int i, j, n;
n = data.size();
for (i = 0; i < (1 << n); i++) {
for (j = 0; j < n; j++) {
if (i & (1 << j)) {
cout << data[j] << " ";
}
}
cout << "\n";
}
}
/* function ends */
#define MAX 200005
#define INF 0X7FFFFFFF
struct EDGE {
int node;
int cost;
EDGE(int n, int c)
{
node = n;
cost = c;
}
};
struct compare
{
bool operator()(pii &a, pii &b)
{
return a.first > b.first;
}
};
vector<EDGE> adjList[MAX];
void clearAll()
{
for (int i = 0; i < MAX; i++) {
adjList[i].clear();
}
}
int PrimMST(int source, int nodes)
{
priority_queue<pii, vector<pii>, compare> PQ;
vector<int> key(nodes + 1, INF);
vector<bool> inMST(nodes + 1, false);
int u, v, w, ans = 0;
key[source] = 0;
PQ.push(make_pair(key[source], source));
while (!PQ.empty()) {
u = PQ.top().second;
inMST[u] = true;
PQ.pop();
for (int i = 0; i < adjList[u].size(); i++) {
v = adjList[u][i].node;
w = adjList[u][i].cost;
if (!inMST[v] && w < key[v]) {
key[v] = w;
PQ.push(make_pair(key[v], v));
}
}
}
for (u = 0; u < nodes; u++) {
ans += key[u];
}
return ans;
}
int main()
{
#ifndef ONLINE_JUDGE
freopen("in.txt", "r", stdin);
freopen("out.txt", "w", stdout);
#endif
fastIO;
int numberOfNodes, numberOfEdges, u, v, c, sumOfAllEdgeCost;
while (cin >> numberOfNodes >> numberOfEdges && numberOfNodes) {
clearAll();
sumOfAllEdgeCost = 0;
for (int i = 1; i <= numberOfEdges; i++) {
cin >> u >> v >> c;
adjList[u].push_back(EDGE(v, c));
adjList[v].push_back(EDGE(u, c));
sumOfAllEdgeCost += c;
}
cout << sumOfAllEdgeCost - PrimMST(0, numberOfNodes) << endl;
}
return 0;
}